Sole device

ABSTRACT

The invention relates to a sole device ( 10 ) for shoes, in particular for ballet shoes, comprising: a backbone sole ( 12 ) having a plurality of vertebral bodies ( 14 ), which are connected to one another by joint portions ( 16 ); and intermediate spaces ( 18 ) between the vertebral bodies ( 14 ), which intermediate spaces are associated with the joint portions ( 16 ), the sole device also comprising a plurality of sticks ( 20 ) for inserting into the intermediate spaces ( 18 ). According to the invention, at least two of the plurality of sticks ( 20 ) have different thicknesses and/or cross-sections and at least one of the intermediate spaces ( 18 ) is designed to alternatively receive sticks ( 20 ) having different thickness and/or cross-sections.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage filing under 35 U.S.C. § 371 of International Application No. PCT/EP2020/051592, filed Jan. 23, 2020, titled SOLE DEVICE, which claims priority from German Patent Application No. 10 2019 102 107.3, filed Jan. 29, 2019, the disclosures of both of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a sole device, in particular for ballet shoes, comprising a backbone sole with a plurality of vertebral bodies, which are connected to one another by joint portions, and intermediate spaces between the joint portions which are associated with the joint portions, wherein the sole device further comprises a plurality of sticks for inserting into the intermediate spaces.

BACKGROUND

Such a sole device for the special situation of use as an inner sole in a ballet shoe is known from EP 2742818 A1 of the Applicant.

The insertion of a stick into an intermediate space between two vertebral bodies, and the removal of an inserted stick from the intermediate space, defines the flexural behaviour of the sole device in the region of the joint portions adjacent to the intermediate space, between the two vertebral bodies. The sole device is in principle freely movable upwards, but downwards its flexibility is defined by the vertebral bodies and sticks, which are also designated as intervertebral disks. In this situation, “upwards” designates that side of the sole device on which the user stands, while “downwards” designates the side which points to the ground when walking. An integrated rubber layer produces a permanent and elastic tension on the underside of the backbone sole. At the same time, the rubber layer serves as a barrier against the lateral slipping of the stick. With the stick inserted, the course run of the sole device in the region of the intermediate space into which the stick is inserted remains straight. Without a stick, the sole device would be bent downwards at this point by the tension of the rubber layer or by loading until the point at which the vertebral bodies struck against one another.

The sticks of the generic sole device are in principle of the same shape, with the exception of their length, such that, in the region of the heel, where this known sole device exhibits a lesser width, shorter sticks can be used than in the region of the forefoot, where the sole device is wider.

Accordingly, the individual bending behaviour of this known sole device is controlled exclusively by yes/no decisions, namely whether and into which intermediate spaces are inserted. The angle behaviour of the sole device is in this situation definitely defined in the vertebral disk regions, i.e. the intermediate spaces which are able to accommodate a stick, namely straight or angled. The adjustable cambered course runs of the sole devices accordingly exhibit substantial jump increments, and therefore do not attain the capability of adjustment to a fine anatomical degree. Likewise, it is not possible to adjust a supportive negative flexure of the sole device, with which it can also adopt a stable shape upwards into the camber of the foot. The traditional pointed shoe further differentiates different degrees of hardness of the inner sole, which are among the most significant variables with pointed shoes. In respect of medical considerations related to dancing, a rapidly adjustable degree of hardness is desirable, among other reasons due to the fact that a warm foot requires another form of support by the inner sole than a cold foot. In the prior art, however, there is no variable hardness behaviour of the sole device which is capable of adjustment.

The object of the present invention is therefore to develop a generic sole device further in such a way that the variability and precision of its flexural behaviour is improved.

SUMMARY

According to the invention, this object is solved in that at least two of the plurality of sticks exhibit different thicknesses and/or cross-sections, and that at least one of the intermediate spaces is configured in such a way as to alternatively receive sticks having different thicknesses and/or cross-sections.

Accordingly, it is possible for different types of sticks to be inserted into one and the same intermediate space of the sole device according to the invention, namely sticks with different thicknesses and/or cross-sections. As a result of this, the course run of the joint portion which is associated with this intermediate space can be substantially more finely adjusted than in the prior art, which makes provision for such an intermediate space to have only two states, with a stick inserted or completely removed.

In a particularly preferred embodiment, a plurality, and preferably all, of the intermediate spaces are configured such as to alternatively receive sticks with different thicknesses and/or cross-sections. In the total of all the intermediate spaces, therefore, the flexure of the sole device according to the invention can be adjusted precisely to the respective user, and to the planned situation of use. In this situation, it is particularly simple to produce a variant with which all the intermediate spaces are of the same conceptual design, such as rectangular, and have the same width.

For this purpose provision is made for at least one of the sticks to exhibit such a thickness and/or such a cross-section that, in a state in which it is inserted into an intermediate space, it provides a straight course run for the joint portion associated with it. In such a region the sole device according to the invention then does not exhibit any flexure.

In addition or as an alternative, provision is made to this purpose that at least one of the sticks exhibits such a thickness and/or such a cross-section that, in the state in which it is inserted into the intermediate space, it presses the vertebral bodies adjacent to the intermediate space apart from one another. The insertion of such a stick into an intermediate space therefore has the effect of a local flexure upwards of the sole device according to the invention, which is usually designated as a negative flexure. The replacement of such a stick by a stick with greater thickness presses the adjacent vertebral bodies still further apart, and therefore increases the local negative flexure.

In addition or as an alternative, provision is also made to this purpose that at least one of the sticks exhibits such a thickness and/or such a cross-section that, in the state in which it is inserted into an intermediate space, it allows for the vertebral bodies adjacent to the intermediate space to be brought closer to one another. The insertion of such a stick, which does not completely fill an intermediate space, into this intermediate space therefore allows, with the corresponding loading of the sole device according to the invention, a local flexure downwards, which is usually designated as positive flexure.

Provision is preferably made in this situation for at least one of the intermediate spaces to exhibit a rectangular or trapezoidal cross-section. Such a configuration is particularly versatile, since sticks with different cross-section geometries can be used, such as sticks with a likewise rectangular or trapezoidal cross-section, or also sticks with circular cross-section, for example.

As an alternative or in addition, however, it is also possible for at least one of the sticks to exhibit a cross-section which is not rotationally symmetric, and is configured such as to be rotatably inserted in at least one of the intermediate spaces. Instead of replacing a narrow stick by a wider stick, for example, in order to spread the adjacent vertebral bodies further apart, and to increase the local flexure of the sole device according to the invention in the negative direction, it is then possible, by rotating the stick in a direction such that the diameter of the stick increases between the two adjacent vertebral bodies, and so achieve the same effect.

To this purpose, the at least one rotatable stick exhibits an oval cross-section. It can then be steplessly rotated in its intermediate space, which allows for a particularly fine adjustment of the local flexure of the sole device according to the invention.

In an embodiment which is particularly preferred in the technical production respect, the at least one rotatable stick can exhibit in this case an elliptical cross-section.

In the embodiments described heretofore, the sole device according to the invention can be adjusted, at the beginning of the use of a shoe, to the foot of the respective user, and the sticks then remain permanently in their respective intermediate spaces, for example by fixed locking in position. Preferably, however, provision is made for the sticks to be configured for detachable insertion into the intermediate spaces. This applies in particular to embodiments in which the sticks are not rotatably received in the intermediate spaces. For example, the sticks can exhibit a shape with bays on the under side, in which the rubber layer of the sole device runs, already referred to, and imposes loading onto the sticks in the direction of the vertebral bodies and the joint portions, as is explained in the generic EP 2742818 A1, the disclosure of which is hereby adopted by reference in respect of the shape of the sticks and of the intermediate spaces and the function of the rubber layer in the detachable holding of the sticks.

The present invention further relates to a shoe, comprising a sole device as described heretofore.

Such a shoe can be, for example, a ballet shoe, an orthopaedic shoe, a sports shoe, or a running shoe.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the device are explained hereinafter on the basis of the Figures, as non-restrictive examples. The Figures show:

FIG. 1 A perspective view of an embodiment of the sole device according to the invention from obliquely beneath, in use in a ballet shoe in the demi-pointe position;

FIG. 2 a schematic view of the sole device according to the invention from FIG. 1 from beneath, with sticks above represented in perspective.

FIG. 3 a schematic side view of an embodiment of the backbone sole and of the sticks of a sole device according to the invention, before the insertion of the sticks into the intermediate spaces;

FIG. 4 a schematic side view of the backbone sole and of the sticks from FIG. 3 after the insertion of the sticks into the intermediate spaces;

FIG. 5 a schematic side view of another embodiment of the backbone sole and of the sticks;

FIG. 6 a schematic side view of a further embodiment of the backbone sole and of the sticks;

FIG. 7 a schematic side view of the sole device according to the invention, with the sticks inserted into the intermediate spaces, in order to illustrate the flexure zones of the sole device;

FIG. 8 a schematic side view similar to FIG. 7, in order to illustrate the bending effect and the heel angle effect;

FIG. 9 four schematic side views of the sole device according to the invention, with differing degrees of hardness adjusted;

FIG. 10 three schematic side views of foot positions with the use of the sole device according to the invention in a ballet shoe; and

FIG. 11 three schematic side views of foot positions with the use of the sole device according to the invention with differently adjusted degrees of hardness in a ballet shoe, in a pointe position.

DETAILED DESCRIPTION

FIG. 1 shows a perspective view of an embodiment of the sole device 10 according to the invention from obliquely beneath, in use in a ballet shoe in the demi-pointe position. FIG. 2 shows a schematic view of the sole device 10 according to the invention from FIG. 1, from beneath, and FIG. 3 shows a schematic side view.

The sole device 10 comprises a backbone sole 12 with a plurality of vertebral bodies 14, which are connected to one another by joint portions 16. Formed between each two adjacent vertebral bodies 14 is an intermediate space 18, which in the schematic side view from FIG. 3 is located beneath a joint portion 16 associated with it in each case. All the intermediate spaces 18 exhibit essentially the same width, and are each configured so as to be able to receive a stick 20.

On the under side of the backbone sole 12, visible in particular in FIG. 2, a rubber layer 22 is provided. In FIG. 2 the rubber layer is in the region of the right heel, and is secured to the left forefoot region of the under side of the backbone sole in FIG. 2 in such a way that it is in contact in taut tension with the vertebral bodies 14, and closes off the intermediate spaces 18 downwards. The rubber layer 22 produces a permanent elastic tension on the under side of the backbone sole 12, and therefore provides the backbone sole 12 with the necessary counter-tension, like a muscle. The sticks 20 are provided on their under side with suitably dimensioned bays, such as can be seen in the upper part of FIG. 2 in the perspective representation of the sticks 20. When a stick 20 is inserted into an intermediate space 18, the rubber layer 22 grips into its bay, and secures it against lateral slippage or falling out. In other words, the rubber layer 22 functions as a barrier for the inserted sticks 20. Likewise, the rubber layer 22 stabilizes and synchronises the vertebral bodies 14 of the backbone sole 12.

In FIGS. 1 and 2 a double arrow indicates in each case that a stick 20 which is to be replaced is pressed out of an intermediate space 18 by a stick 20 which is to be newly inserted. If the newly inserted stick 20 has a different thickness and/or different cross-section to the stick 20 being replaced, this allows for the flexure of the backbone sole 12 to be changed locally. For the replacement, the newly inserted stick 20 needs only exert a somewhat sideways pressure on the stick 20 which is to be inserted in order to press it out, while the new stick 20 engages into the backbone sole 12. Due to the permanent exchange capacity of sticks 20 with different angle arrangements and/or different widths, the effect is a course run of the backbone sole 12 which can at any time be varied, supported, and precisely angled, and which, as required, can be kept straight or defined with a precise degree inclined upwards or downwards. It is therefore possible for all requirements on inner soles for ballet pointe shoes or other shoes to be ensured, with the variability of one single backbone sole 12. This is explained in detail hereinafter:

FIG. 3 shows a schematic side view of an embodiment of the backbone sole 12 and of the sticks 20 of a sole device 10 according to the invention before the insertion of four different sticks 20 into intermediate spaces 18, and FIG. 4 shows the situation after the insertion of the sticks 20 into the intermediate spaces 18. In this particularly simply configured embodiment, all the intermediate spaces 18 have the same shape and width.

Next, the insertion of the left of the four sticks 20 is seen in section “a” of FIGS. 3 and 4. This stick 20 exhibits a rectangular cross-section and a thickness which correspond to the width and the cross-section of an intermediate space 18. In other words, the perpendicular side faces of this stick 20 enclose an angle of 0° with the perpendicular side faces of the intermediate space 18. The insertion of the stick 20 into the intermediate space 18 is symbolised in FIG. 3 by an upwards arrow. In the state inserted into the intermediate space 18, which is shown in FIG. 4, section “a”, this stick 20 therefore provides the associated joint portion 16 above the intermediate space 18 with a straight course run, identified in the Figure by “180°”. This stick 20 therefore basically behaves in a neutral manner in respect of the local flexure of the backbone sole 12, but prevents a local flexure of the backbone sole 12 downwards in this region.

Next, the insertion of the adjacent stick 20 in section “b” of FIGS. 3 and 4 is seen, i.e. the second stick 20 from the left. This stick 20 exhibits a trapezoidal cross-section, wherein its thickness in its upper region corresponds to the width of the empty intermediate space 18, and increases from the top downwards. The left side wall of this stick 20 encloses an outer angle of −a° with the left side wall of the empty rectangular intermediate space 18, and the right side wall of this stick 20 encloses an outer angle of −b° with the right side wall of the empty rectangular intermediate space 18. As the Figure shows, negative angles designate a course run with which the side wall is inclined outwards from the top downwards. The insertion of the stick 20 into the intermediate space 18 is symbolized in FIG. 3 in turn by an upwards arrow. At the insertion into the intermediate space 18, this stick 20 presses the adjacent vertebral bodies 14 apart from one another in their lower region. In the state inserted into the intermediate space 18, which is shown in FIG. 4, section “b”, this stick 20 therefore provides the associated joint portion 16 with a negative flexure over the intermediate space 18, i.e. a course run which is locally inclined upwards, identified in the Figure by “180°−a°−b°”. In other words, this stick 20 has the effect of negative flexure about an angle which corresponds to the sum of its outer angles. This can be identified by the marking “−” represented on the stick 20. In order to achieve the effect described, the sticks 20 can be made of a material, in particular a plastic material, which exhibits a greater hardness and strength than the material of the backbone sole 12, at least than the joint portions 16. In other words, by the suitable selection of different materials for the sticks 20 on the one hand, and of the different regions of the backbone sole 12 on the other, it can be ensured that the pressing of a stick 20 into an intermediate space 18 will lead to a flexure of the associated joint portion 16, as being the material region which is most affected by flexure. As a rule, the sticks 20 on the one hand and the backbone sole 12 on the other are made of the same material, in particular a plastic material. The tear-resistant and minimally extendible plastic used provides a certain flexure, which decreases accordingly with the increasing thickness of the material. That is to say, the flexure capacity achieved of the thin-layered material in the joint portions 16 of the backbone sole 12 is sufficient for the flexure effects according to the invention, while the thicker but otherwise same material of the vertebral bodies 14 and sticks 20 transfer the forces with the necessary stability. For the sticks 20 it is therefore not necessary for another material to be used, since they do not disperse the forces over their longitudinal configuration, but transversely, where practically no relevant elasticity effect can be identified.

In any event, the material of the backbone sole 12, its vertebral bodies 14, and joint portions 16 must as a rule be produced as a single piece by injection moulding, and must be sufficiently strong and stable to be able to sustain the necessary support pressure when the shoe is used.

Now the insertion of the adjacent stick 20 in section “c” of FIGS. 3 and 4 is considered, i.e. the second stick 20 from the right. This stick 20 exhibits a trapezoidal cross-section, wherein its thickness in its upper region corresponds to the width of the empty intermediate space 18, and decreases from the top downwards. The left side wall of this stick 20 encloses an angle of c° with the left side wall of the empty rectangular intermediate space 18, and the right side wall of this stick 20 encloses an angle of d° with the right side wall of the empty rectangular intermediate space 18. Positive angles designate, as shown in the Figure, a course run with which the side wall is inclined inwards from the top downwards. The insertion of the stick 20 into the intermediate space 18 is in turn symbolized in FIG. 3 by an upwards arrow. At the insertion into the intermediate space 18, this stick 20 allows for the vertebral bodies 14 adjacent to the intermediate space to come closer to one another in their lower region. In the state inserted into the intermediate space 18, which is shown in FIG. 4, section “c”, this stick 20 therefore provides the associated joint portion 16 with positive flexure over the intermediate space 18, i.e. a course run locally inclined downwards, identified in the Figure by “180”+c°+d°. In other words, this stick 20 has the effect of a positive flexure about an angle which corresponds to the sum of its outer angles. This can be identified by the marking “+” represented on the stick 20.

Now the insertion of the adjacent stick 20 in section “d” of FIGS. 3 and 4 is considered, i.e. the right stick 20. This has a trapezoidal cross-section similar to the adjacent stick 20 in section “c” of FIGS. 3 and 4, although the angles e° and r, which its side walls enclose with the left and right side walls respectively of the empty rectangular intermediate space 18, are greater than the angles c° and d° respectively of the adjacent stick 20. In comparison with the adjacent stick 20 in section “c”, the right stick 20 in section “d” of FIGS. 3 and 4 therefore provides the associated joint portion 16 with a still stronger positive flexure, i.e. a course run which is locally still more strongly inclined downwards, identified in the Figure by “180”+e°+fp. This can be identified by the marking “++” represented on the stick 20. Overall, the sticks 20 can exhibit different finely-stepped angles, which can also be combined almost at will with the static angles of the backbone sole 12. In FIG. 4 can also be seen the large-surface and stable force connection between the vertebral bodies 14 and sticks 20, as a result of which it becomes possible, among other considerations, to reduce the material thickness of the backbone sole 12 in relation to the prior art.

It is understood that the sole device 10 according to the invention can comprise not only sticks 20 with trapezoidal forms in differing degrees for positive flexures, but also sticks 20 which are correspondingly shaped with trapezoidal forms in differing degrees for negative flexures, similar to the stick 20 shown in section “b” of FIGS. 3 and 4. It is likewise understood that not only can two sticks 20 with trapezoidal forms in differing degrees be provided for each flexure direction, but also a far greater number, in order to allow for the finest possible gradation of the local flexure at each intermediate space 18.

It is likewise understood that a straight course run, as in section “a” of FIGS. 3 and 4 can be achieved not only by the insertion of a rectangular stick 20 into a rectangular intermediate space 18 with the same width, but also, for example, by the insertion of a trapezoidal stick 20 into a complementary trapezoidal intermediate space 18, by the insertion of a triangular stick 20 into a complimentary triangular intermediate space 18, etc.

Expressed in general terms, the geometry of the intermediate spaces 18 can exhibit a multiplicity of angles and shapes, which are then either mirrored by the cross-sections and/or widths of the sticks 20 in order to ensure a straight course run of the backbone sole 12, or with alternative cross-sections and/or thicknesses are added to the cross-sections and/or thicknesses of the intermediate spaces 18 or subtracted from them, in order to control the flexural behaviour of the backbone sole 12 with a precise degree arrangement.

FIG. 5 shows a schematic side view of another embodiment of the backbone sole 12 and stick 20 according to the invention. The left stick 20 corresponds to that in section “a” of FIGS. 3 and 4. It is therefore rectangular and has a thickness and a cross-section of such a type that it fits exactly into an empty intermediate space 18. With regard to local flexure, this stick therefore again is neutral in behaviour, i.e. it leaves the local straight run of the associated joint portion 16 unaffected, but it does block the adjacent vertebral bodies from approaching close to one another, and therefore changes the occurrence of a positive flexure locally.

The middle stick 20 in FIG. 5 is likewise rectangular, but its thickness is greater than the width of an empty intermediate space 18. At the insertion into the intermediate space 18, this stick 20 therefore has the effect locally of a negative flexure of the backbone sole 12, namely a local flexure upwards. Naturally, this stick 20 also blocks the adjacent vertebral bodies 14 from approaching one another, and therefore locally prevents the occurrence of a positive flexure.

The right stick 20 in FIG. 5 is likewise rectangular, but its thickness is smaller than the width of an empty intermediate space 18. When this stick is inserted into an intermediate space 18, it therefore allows the adjacent vertebral bodies 14 to move apart from one another under loading, until they come in contact at the stick 20. In other words, this stick 20 allows locally for a predetermined positive flexure of the backbone 12, namely a local flexure downwards.

The embodiment shown in FIG. 5 of the sole device 10 according to the invention is more economical to produce, since rectangular sticks 20 exclusively are to be produced, although the force connection between the vertebral bodies 14 and the sticks 20 is less than in the embodiment shown in FIGS. 3 and 4. Accordingly, the embodiment from FIG. 5 should be used in cases with less stress on the sole device 10.

FIG. 6 shows a schematic side view of a further embodiment of the backbone sole 12 and of the sticks 20, which in this embodiment exhibit an oval cross-section. The sticks 20 in this embodiment are entirely surrounded by the material of the backbone sole 12, such that joint portions 16 exist both as well as below a stick 20, which connect the adjacent vertebral bodies 14 with one another.

In this embodiment, the sticks 20 are received so as to be rotatable in their respective intermediate spaces 18, which are delimited to the side by adjacent vertebral bodies 14 and upwards or downwards respectively by adjacent joint portions 16. By rotation, different diameters of a stick 20 can be adjusted between the two adjacent vertebral bodies 14. If a stick 20 is rotated, for example, into a position in which its longer diameter runs essentially parallel to the longitudinal direction of the backbone sole 12, then the adjacent vertebral bodies 14 are pressed apart to the maximum, which gives the backbone sole 12 locally a negative flexure, i.e. a flexure upwards; compare, for example, in FIG. 6 the second stick 20 from the left.

Conversely, if a stick 20 is rotated into a position in which its short diameter runs essentially parallel to the longitudinal direction of the backbone sole 12, then the adjacent vertebral bodies 14 can, under loading, be moved onto one another, which gives the backbone sole 12 a positive flexure locally, i.e. a flexure downwards; compare, for example, in FIG. 6 the right stick 20.

The embodiment shown in FIG. 6 with rotatable sticks 20, which are completely surrounded by sole material, is conceivable in particular for sports shoes with softer soles, wherein the elasticity of the material makes possible the expansion of the oval stick 20 in the surrounding sole material. The effect in this situation is, in particular, a variable elastic course run of the sole tension. Such oval sticks 20 could also be used, however, with other types of shoes, in particular ballet shoes, and also introduced into the rectangular or trapezoidal intermediate spaces 18, shown in FIG. 3, and take effect accordingly on rotation. In both cases, the oval stick 20 can be fixed and rotated either by screw thread arrangements or by way of engagement mechanisms such as, for example, toothed wheel mechanisms.

FIG. 7 shows a schematic side view of the sole device 10 according to the invention, with different sticks 20 inserted into the intermediate spaces, in order to make clear the flexure zones of the sole device 10. The forefoot region of the sole device 10 is on the left in this Figure, and the heel region on the right. FIG. 8 shows a schematic side view similar to FIG. 7, in order to illustrate the forward flexure effect and the heel angle effect, and FIG. 9 shows four schematic side views of the sole device 10 according to the invention, with the assistance of different sticks 20 of differently adjusted degrees of hardness. The forefoot region of the sole device 10 is at the bottom in all the side views of this Figure, and the heel region at the top. FIG. 10 illustrates schematic side views of foot positions with the use of the sole device according to the invention in a ballet shoe when walking (top) and demi-pointe (bottom left), as well as on pointe (bottom right), and FIG. 11 shows schematic side views of foot positions with the use of the sole device 10 according to the invention, with differently adjusted degrees of hardness in a ballet shoe when standing on pointe.

The backbone sole 12 shown by way of example in all these Figures are intended overall to comprise a total of ten intermediate spaces 18, into which in each case sticks 20 are inserted. It is understood that the backbone sole 12 can also have a different number of intermediate spaces 18, and that individual intermediate spaces 18 can also remain empty, depending on the use of the shoe, the inner sole of which comprises the backbone sole 12 according to the invention.

The section in FIG. 7, marked with a broken line and designated by “A”, represents a zone of free movement up to demi-pointe, also designated as the “demi-pointe zone”. In this example, in this zone are located the six frontmost sticks 20, which make it possible for the backbone sole 12 to allow the foot to roll and to stand on demi-pointe, since the backbone sole 12 is not limited in flexure upwards, while by contrast the flexure downwards is controlled by the inserted stick 20.

The section in FIG. 7, marked by a broken line and designated by “B”, which in this example relates to the rear half of the section “A” with three sticks 20, represents a zone for the adjustment of the forward flexure, i.e. of the degree of hardness.

The traditional pointe shoe distinguishes different degrees of hardness of the inner sole. The height and degree of flexure of the backbone sole 12, adjustable by alternative sticks 20, define the angle which the outer pointe shoe can adopt when standing en pointe; compare the upper shaded region identified by “B” in FIG. 8, and the four schematic side views in FIG. 9. More flexure leads to the shoe being given more space by the backbone sole 12 in order to tilt forwards, as shown in FIG. 11A, while less forward flexure forces the shoe back, see FIG. 11B. With the optimum adjustment of forward flexure and heel angle, the backbone sole 12 develops its best support function, which is represented in FIG. 11C. Accordingly, in this way pressure will already be dispersed in the region of the heel angle, and the forefoot will be relieved of stress in the cap.

The section marked with a broken line and designated by “C” in FIG. 7 represents a zone for the adjustment of the heel angle; compare the lower shaded region identified by “C” in FIG. 8 and the four schematic side views in FIG. 9. In this example, the section “C” comprises the rear four sticks 20 of the backbone sole 12. With the foot extended, a perceptible fold is shown at the transition from the foot sole to the heel. An inner sole for pointe shoes should therefore be in a position to adjust this fold in an optimum manner in order on the one hand to give the heel the necessary space, and, on the other, not to lose contact at any point of the supporting contact of the inner sole to the foot. The heel angle is differently arranged for each foot, and with the sole device 10 according to the invention can be adjusted to a precise angle. In the rear region of the backbone sole 12, the height and the degree of the heel angle are precisely defined. In this situation, “height” designates the position of the stick 20 which determines the angle for the heel angle required. In FIGS. 7-9, these sticks 20, marked in black and determining the angle are located at the positions 9 and 10, but other positions can also be selected, for example 8 and 9, or also 7 and 8, depending on the size and individual anatomy of the foot. Shown in FIGS. 7-9 in each case is the same heel angle setting, such that differences in the forwards flexure effect, referred to as the “hardness setting”, are better visible. The “degree of the heel angle” designates the number of sticks 20 used, and their angle setting. Accordingly, the unique support function of the backbone 12 is guaranteed, which already reduces the pressure at the point of the heel angle, and, as a result, in medical terms the stress on the forefoot in the cap of the pointe shoe is already significantly relieved, as is represented in FIG. 11 C.

By way of negatively-angled sticks 20, as represented by way of example in section “b” of FIGS. 3 and 4, with the sole device 10 according to the invention the situation is achieved in which the backbone sole 12 can be flexed upwards with an exactly defined negative flexure, and the camber of the foot can be followed anatomically precisely. Accordingly, the invention of the backbone sole 12 guarantees a better support function, which standing on pointe depends in particular on the precise location of the adjustment for the heel angle. The negative flexure of the stick 20 additionally compensates for the inherent expansion of the material of the backbone sole 12. This guarantees a higher absorption of force in the heel angle region, and the shock-absorbing properties of the backbone sole 12 are more effective. In FIG. 9, the effect of the negative flexure is represented as exaggerated for the purpose of easier representation. 

1. A sole device for shoes, in particular for ballet shoes, comprising: a backbone sole with a plurality of vertebral bodies, which are connected to one another by joint portions, and intermediate spaces, associated with the joint portions, between the vertebral bodies, wherein the sole device further comprises a plurality of sticks for inserting into the intermediate spaces, and wherein at least two of the plurality of sticks exhibit different thicknesses and/or cross-sections, and that at least one of the intermediate spaces is configured such as to receive alternatively sticks with different thicknesses and/or cross-sections.
 2. The sole device according to claim 1, wherein a plurality, and preferably all, of the intermediate spaces are configured such as to receive alternatively sticks with different thicknesses and/or cross-sections.
 3. The sole device according to claim 1, wherein at least one of the sticks exhibits such a thickness and/or such a cross-section that, in a state in which it is inserted into an intermediate space, it provides a straight course run for the associated joint portion.
 4. The sole device according to claim 1, wherein at least one of the sticks exhibits such a thickness and/or such a cross-section that, in the state in which it is inserted into an intermediate space, it presses the vertebral bodies adjacent to the intermediate space apart from one another.
 5. The sole device according to claim 1, wherein at least one of the sticks exhibits such a thickness and/or such a cross-section that, in the state when inserted into an intermediate space, it allows for the vertebral bodies adjacent to the intermediate space to come closer to one another.
 6. The sole device according to claim 1, wherein at least one of the intermediate spaces exhibits a rectangular or trapezoidal cross-section.
 7. The sole device according to claim 1, wherein at least one of the sticks exhibits a non-rotationally symmetric cross-section, and is configured such as to be rotatably inserted into at least one of the intermediate spaces.
 8. The sole device according to claim 7, wherein the at least one rotatable stick exhibits an oval cross-section.
 9. The sole device according to claim 8, wherein the at least one rotatable stick exhibits an elliptical cross-section.
 10. The sole device according to claim 1, wherein the sticks are configured for detachable insertion into the intermediate spaces.
 11. A shoe, comprising a sole device according to claim
 1. 12. The shoe according to claim 11, in which the shoe is selected from the group consisting of a ballet shoe, an orthopedic shoe, a sports shoe, and a running shoe. 